ABSTRACT. This study aimed to compare results of genome-wide associations obtained from various methodologies for GWAS when applied to two lines of broiler chicken. Each line contained >250k birds with 3 traits and 5k SNP60k genotypes. Methods included single-step GWAS, single marker model and BayesB. Mannhattan plots were based on variances of 20-SNP segments, as shorter segments produced noisy plots. Only a few segments explained >1 % of the additive variance. One segment explained >20% variance in BayesB but 3% with ssGWAS and 16k genotypes, but no segment explained >1% of the variance. Strength of associations strongly depends on methodologies and details of implementations.